Enhancing recuperators performance in supercritical CO2 Brayton cycle of solar power plants through ribbed heat transfer plates

Abstract

Sixteen diverse combinations of ribbed heat transfer plates (HTPs), comprising continuous and discontinuous rib configurations, are investigated as potential replacements for traditional smooth HTPs in both the low-temperature recuperator (LTR) and high-temperature recuperator (HTR) of supercritical CO2 Brayton cycles. The findings indicate that the impacts of the introduced HTPs are more significant under the operating conditions of the LTR than those of the HTR. Generally, the incorporation of denser ribs at the upstream sections of both the hot and cold flow paths leads to a significant enhancement in j-factor values. On the hot side of the LTR, these increases exceed 60%, while on the cold side, they surpass 40%. It is also observed that variations in rib pitch exert a more substantial influence on thermal performance compared to alterations in rib length. When comparing non-uniform rib patterns, it is found that the use of ribs with variable lengths increases f-factor values, whereas the design of HTPs with variable rib pitches decreases these values. The design of HTPs with a non-uniform arrangement of rib pitch yields the best overall performance in the LTR. The performance index values for the hot-side and cold-side of this model reach 1.39 and 1.26, respectively.